1. Field of the Invention
The present invention relates to a photographing apparatus, and more particularly, relates to a photographing apparatus carrying out photographing in combination with an external flash or a built-in flash.
2. Description of the Related Art
Conventionally, a focal plane shutter is frequently used in a single-reflex camera. When carrying out photographing by using a flash, it is possible to illuminate an object uniformly by flash light emission at the moment when a shutter is fully opened at a shutter speed slower than a shutter speed at which a focal plane shutter is fully open (so-called flash synchronization speed). Furthermore, when carrying out the flash photographing in a shutter speed not slower than the flash synchronization speed, it is possible to illuminate the object uniformly by a light emission method called a flat light emission method in which flash light is continuously emitted to provide an effect similar to that of ambient light (refer to Japanese Patent Application Laid-Open Publication No. 2001-215574 (disclosed on Aug. 10, 2001)).
In the camera performing exposure by using the focal plane shutter, the same shutter speed as a curtain speed of the focal plane shutter, for example, a shutter speed of approximately 1/200 seconds, is the highest speed of the flash synchronization. Accordingly, when the flash light emission is used in a photographing scene such as daytime synchronization, it is necessary to set the shutter speed to be a shutter speed slower than the flash synchronization speed and a photographing condition is restricted. Furthermore, when the flash synchronization is carried out at a high shutter speed by the flat light emission, the cost of the apparatus is considerably increased because of a scale-up of a flash light emission circuit, a higher complexity of light emission control, and the like, and further a light emission amount cannot be increased because the light emission is carried out continuously and a photographing condition is restricted.
Meanwhile, a MOS type imaging element is known to employ a read-out method of a lump shutter (called global shutter) method which makes the exposure periods of all the pixels uniform (refer to Japanese Patent Application Laid-Open Publication No. 2008-28517 (disclosed on Feb. 7, 2008)). When photographing is carried out by the use of an imaging element capable of the read-out of this global shutter method, the shutter speed can be controlled electronically and it is possible to realize a high shutter speed of higher than 1/10000 seconds, for example. Further, when the photographing is carried out in combination with a flash apparatus, the flash synchronization can be performed in principle even at a high shutter speed such as 1/10000 seconds.